1. Field of the Invention
The present invention relates to a manufacturing method and apparatus of a fiber reinforced composite member, in which a plurality of products can simultaneously be manufactured.
2. Description of the Related Art
In order to raise the performance of a rocket engine using NTO/N2H4, NTO/MMH, and the like as impelling agents, heat-resistant temperature of a combustor (thrust chamber) is requested to be raised. For this purpose, a coated niobium alloy having a heat-resistant temperature of about 1500° C. has heretofore been used as a chamber material for many rocket engines. However, this material is disadvantageously heavy because of its high density, low in high-temperature strength, and has a short coating life.
On the other hand, since ceramic is high in heat resisting properties but disadvantageously brittle, a ceramic matrix composite member (hereinafter abbreviated as CMC) has been developed by reinforcing the ceramic with ceramic fiber. Specifically, a ceramic matrix composite member (CMC) comprises ceramic fiber and ceramic matrix. Additionally, in general the CMC is indicated as ceramic fiber/ceramic matrix by its material (e.g., when both are formed of SiC, SiC/SiC is indicated). Additionally, the ceramic matrix composite member (CMC) will be described hereinafter in detail, but the present invention is not limited to this, and can similarly be applied also to carbon-based composite members such as C/C, C/SiC and SiC/C.
Since CMC is light-weight and high in high-temperature strength, it is a remarkably prospective material for the combustor (thrust chamber) of the rocket engine, further a fuel piping in a high-temperature section, a turbine vane of a jet engine, a combustor, an after-burner component, and the like.
However, the conventional CMC cannot hold its hermetic properties and is disadvantageously low in resistance to thermal shock. Specifically, for the conventional CMC, after a predetermined shape is formed of ceramic fibers, a matrix is formed in a gap between the fibers in so-called chemical vapor infiltration (CVI) treatment. However, a problem is that it takes an impractically long time (e.g., one year or more) to completely fill the gap between the fibers by the CVI. Moreover, in a high-temperature test or the like of the conventional CMC formed as described above, when a severe thermal shock (e.g., temperature difference of 900° C. or more) acts, the strength is drastically lowered, and the CMC can hardly be reused.
Therefore, the conventional ceramic matrix composite member (CMC) cannot substantially be used in the combustor (thrust chamber), the fuel piping or another component requiring the hermetic properties and resistance to thermal shock.
In order to solve the aforementioned problem, the present inventor et al. have created and filed a patent application, “Ceramic-based Composite Member and its Manufacturing Method” (Japanese Patent Application No. 19416/1999, not laid yet). The Ceramic-based Composite Member can largely enhance the hermetic properties and thermal shock resistance and it can be for practical use in the thrust chamber, and the like. In the invention, as schematically shown in FIG. 1, after subjecting the surface of a shaped fabric to CVI treatment to form an SiC matrix layer, PIP treatment is performed to infiltrate and calcine a gap of the matrix layer with an organic silicon polymer as a base.
In a manufacture process shown in FIG. 1, from a braiding process (1) to a CVI process (3), a jig or mandrel, for example, of carbon or the like is used to form a fabric 1 in a periphery and subsequently, the CVI treatment is performed. Since matrix is formed in the gap of the fabric 1 by the CVI treatment and a shape is held, in this stage, the mandrel is detached, and subsequent PIP treatment (4) and machining (5) are performed in a conventional art. Additionally, in the braiding process, as schematically shown in FIG. 2, for example, braid weave is used in which a braided thread is alternately and obliquely woven into a middle thread.
In the manufacture process, however, products (hereinafter referred to as CMC product) of the ceramic matrix composite member have heretofore been manufactured individually one by one. In this case, particularly, in the braiding process, when fiber is wound onto the mandrel, the fiber is wound onto an engaging allowance to a textile weaving loom and a portion of the mandrel other than a product portion. Therefore, as compared with the fiber used in the product portion, there are a large proportion of finally wasted fiber, much fiber loss, and the like, and this raises cost. For example, although ceramic fiber used in the CMC product is expensive, in the conventional art, even with a relatively large CMC product (thrust chamber or the like), a fiber effective utilization ratio is only around 20%, and about 80% results in loss.
Moreover, even in the braiding process and the subsequent CVI treatment, PIP treatment and machining, the products are individually treated one by one in the conventional art. Therefore, particularly in the small-sized CMC product, there is a problem that much labor is required for setting/preparation or the like to the apparatus and that productivity is low.